UML Associative Combinatorial aggregation Silly division is not clear

The association is actually from the big aspect, the aggregation is a special kind of association is from the small aspect, the combination is also a kind of special association relation is in the smaller aspect to say.

The association is only said to be connected, this connection is not specific.

The relationship between the two is that there is not only a connection, which is the relation between the whole and the part, and some can leave the whole.

The combination is also said that the two are not only linked, this connection is also the whole and part of the relationship, but the part can not leave the whole two exist. I think the most classic example is the link between activity and fragment. A living combination of relationships.

Summary: You can see that association relationships actually include aggregation and composition. It's just the finer points.

implementation = generalization > Composition > Aggregation > Association > dependency.

UML Associative Combinatorial aggregation Silly division is not clear